Cytologic and histologic diagnosis and significance of controversial squamous lesions of the uterine cervix

The interpretation and precise classification of abnormal squamous cell cha nges in cervicovaginal smears (Pap tests) and tissue samples are challengin g and controversial. The cytologic category atypical squamous cells of unde termined significance and the newly described squamous lesions atypical imm ature metaplasia, papillary immature metaplasia, and transitional cell, met aplasia are representative, Their current status is reviewed, and future di rections aimed at resolving some of the controversy and challenge are sugge sted.